Radiation damage models: comparison between Silvacoand ...

Radiationdamagemodels:comparisonbetweenSilvaco andSynopsys

J.Beyera),M.Bomben b),A.Macchioloa),R.Nisiusa)a)MaxPlanckInstitutfürPhysik,Münchenb)LPNHE&Université ParisDiderot,Paris

20-22.11.201731st RD50Workshop

Introduction&Outline

TCADsimulationbecameanessentialtoolwhendesigningsiliconpixelsensorsandpredictingtheirproperties.

Twomaintoolsareavailable:Silvaco andSynopsysTCADtools.

Aretheycompatiblewithoneanotherindefaultsettingsandsimplequestions?

Docommonradiationdamagemodelsdevelopedwithoneofthem,alsoworkfortheother?

21.11.17 J.BeyerandM.Bomben,ComparingSilvacoandSynopsys 2


SetupforthecomparisonStructureandperspectives

• useasimple2DTCADmodeltoreduceanypossibledifferencearisingfromdifferentimplementationsofthestructure

• aims:• compareCVandIVcurvesfornot-irradiated

caseatvarioustemperatures

• compareCV,IVandCCE(MIPbased)afterirradiation• comparethemodelswithonesimulator• comparethesimulatorswithonemodel


SetupforthecomparisonRadiationdamagemodels

• radiationdamageinTCAD:• bulkdamage:

• trapscharacterisedbyenergylevel,e/hcross-sectionandintroductionrate

• useNewDelhi1 andPerugia20172 irradiationmodelhere

• surfacedamage:• fixedoxidechargeof1×1011cm-2 fornot-irradiatedand

1×1012cm-2 forirradiatedsensors• nointerfacetraps

• radiationlevel:1×1015 neqcm-2

• temperature:-20oC,0oC,20oC

1 R.Dalal etal.,SimulationofIrradiatedSiDetectors,PoS Vertex2014(2015).

2 F.Moscatelli etal.,EffectsofInterfaceDonorTrapStatesonIsolationPropertiesofDetectorsOperatingatHigh-LuminosityLHC,IEEETrans.onNucl.Science2017

Perugia2017

New

Delhi

EnergylevelsbasedonworkofEremin /Verbitskaya /Li


SetupforthecomparisonStructureofinterest

highresistivityp-typebulkmaterial(3×1012cm-3)

n+ pixelimplant

aluminumcontacttoimplant

SiO2

passivation:

electricalcontactontopofthealuminum

simulatedthicknesses:200µm

6

SetupforthecomparisonPhysicsmodels- Synopsys

Mobility:• dopingdependentmobilityaccordingtoMasetti model:

• highfieldsaturationaccordingtoextendedCanali model(Electricalfieldasdrivingforce):

Recombination:• Shokley-Read-Hall(with

doping,temperatureandelectricfield(Hurx lifetime)dependence)

• noavalanche

Band-gapnarrowing• OldSlotboom

FormulasfromSynopsyssDevicemanual


SetupforthecomparisonPhysicsmodels- Silvaco

Mobility:• Lookuptabledependingonconcentrationandsimplepowerlawtemperaturedependence.• Fielddependentmobilitymodel:Caughey andThomasforlowfieldregime;Schwarz andRusse forhighfield

Recombination:• ConcentrationdependentSRHrecombinationterm(Roulston,Arora andChamberlain- Law– Fossum,Leeand

Lee)

Band-gapnarrowing• Klaassen model

Wanttocross-checkphysicsmodelsonebyoneacrossthetwosimulatorsinthefuture!


FirsttestsNot-irradiatedstructure– CVcurves

• comparingCVcurvesatvarioustemperatures• notemperaturedependencebetween

-20oCand20oC

• Synopsysvs.Silvaco• risingetdge matchesperfectly• stepinplateauobservedwithSilvaco

butnotwithSynopsys• butagreementintheimportant

(pre)-depletionregionisat%level

0 100 200 300 400 500 [V]bias V

0

200

400

600

800

1000

1200

1400

1600

3010´]-2

[F-2 C

= 0, Synopsys vs. SilvacoFC2V,

Silvaco - T = 20 CSynopsys - T = 20 CSilvaco - T = 0 CSynopsys - T = 0 CSilvaco - T = -20 CSynopsys - T = -20 C

10kHz


FirsttestsNot-irradiatedstructure– IVcurves

• comparingIVcurvesatdifferenttemperatures

• Synopsysvs.Silvaco• Synopsyspredictsslightlyincreasing

plateaucurrent• differencesbetweenSilvaco and

Synopsysincreasewithincreasingtemperature

• bigdifferenceinpredictedplateau• whatisthecause?

0 100 200 300 400 500 [V]bias V

16-10

15-10

14-10

13-10

12-10

[A]

leak

I

= 0, Synopsys vs. SilvacoFIV,



FirsttestsNot-irradiatedstructure– IVcurves,closerlook

• comparingIVcurvesat20oC,varythecarrierlifetimeτ

• canjointhetwosimulatorsbyartificiallychangingthecarrierlifetime

• thedifferencesindefaultτ betweenSilvacoandSynopsysshouldn’tmatterafterirradiation

0 100 200 300 400 500 [V]bias V

0

0.2

0.4

0.6

0.8

1

1.2

12-10´

[A]

leak

I

Silvaco = 1.0e-5 stSilvaco - = 0.933e-5 stSilvaco - = 1.388e-5 stSilvaco -

tSynopsys - std = 1.0e-5 s tSynopsys - = 1.0e-5 s - no conc. dep.tSynopsys -

IrradiatedStructure– 1×1015neqcm-2

1.comparingPerugiaandNewDelhimodels(Synopsys)

2.comparingSynopsysandSilvaco (Perugiamodel)



Comparisonofmodels- SynopsysIrradiatedstructure– CVcurves

• comparingCVcurvesatvarioustemperatures

• depletionwithPerugia2017inareasonablerangeof100-200V

• smalltemperaturedependence

• depletionwithNewDelhiat650->>2000Vbiasvoltage

• hugetemperaturedependence• expectedgiventheenergylevels

aremuchclosertotheintrinsiclevelthaninPerugiamodel

0 500 1000 1500 2000 [V]bias V

0

200

400

600

800

1000

1200

1400

1600

3010´]-2

[F-2

C

, New Delhi vs. Perugia 20172/cmeq = 1e15 nFC2V,

Perugia, T = 20 CNew Delhi, T = 20 CPerugia, T = 0 CNew Delhi, T = 0 CPerugia, T = -10 CNew Delhi, T = -10 CPerugia, T = -20 CNew Delhi, T = -20 C

10kHz


Comparisonofmodels- SynopsysIrradiatedstructure– IVcurves

• comparingIVcurvesatvarioustemperatures

• significantlyhighercurrentwithNewDelhimodel

• NewDelhipredictsincreasingplateaucurrent,shouldbeduetonodepletionyet

• differencesbetweenthemodelsgetsmallerforincreasingtemperature

0 200 400 600 800 1000 1200 1400 [V]bias V

13-10

12-10

11-10

10-10

9-10

[A]

leak

I

/cm^2, New Delhi vs. Perugia 2017eq = 1e15 nFIV,

New Delhi, T = 20 CPerugia T = 20 CNew Delhi, T = 0 CPerugia T = 0 CNew Delhi, T = -20 CPerugia T = -20 C


Comparisonofmodels- SynopsysIrradiatedstructure– chargecollectionefficiency

• comparingCCEatdifferenttemperatures• temperaturedependenceforPerugia

modelmainlyintherisingedgeinagreementwithdepletionvoltagevariation

• NewDelhimodelseemstoexhibitmoredifferenceforhigherbiasvoltages

• comparingNewDelhiandPerugia2017model• significantlylesschargecollectedusing

NewDelhimodel• plateauisnotyetreachedat1000V• reason:bulknotyetdepleted(C-2V) 100 200 300 400 500 600 700 800 900 1000

[V]bias V0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

CC

E [%

]

, New Delhi vs. Perugia 20172/cmeq = 1e15 nFCCE,

New Delhi, T = 20 CPerugia T = 20 CNew Delhi, T = -20 CPerugia T = -20 C

IrradiatedStructure– 1×1015neqcm-2

1.comparingPerugiaandNewDelhimodels(Synopsys)

2.comparingSynopsysandSilvaco (Perugiamodel)



ComparisonofSimulators- PerugiaIrradiatedstructure– CVcurves

• compareCVcurvesfrombothsimulatorsatdifferenttemperatures• overallgoodagreementbetween

SynopsysandSilvaco• differencesincreasingwithincreasing

temperature• differenceisbetween10V– 30V

0 100 200 300 400 500 [V]bias V

0

200

400

600

800

1000

1200

1400

1600

3010´]-2

[F-2 C

, Synopsys vs. Silvaco, Perugia 20172/cmeq = 1e15 nFC2V,

Synopsys - T = 20 CSilvaco - T = 20 CSynopsys - T = 0 CSilvaco - T = 0 CSynopsys - T = -20 CSilvaco - T = -20 C

10kHz

17

ComparisonofSimulators- PerugiaIrradiatedstructure– closerlook:CVcurves

Tool Silvaco Synopsys

Vdepl [V] ~240 ~160

0 100 200 300 400 500 [V]bias V

0

200

400

600

800

1000

1200

1400

1600

3010´]-2

[F-2 C

= 1e15, T = 20C, Perugia 2017FC2V,

Silvaco

=1e-5s, no avalanche, reduced physicstSynopsys,

• investigatingtheimpactofphysicsmodels

• startwithSynopsysreducedphysicsandadaptedcarrierlifetimetomatchIVnot-irr

10kHz

0 100 200 300 400 500 [V]bias V

0

200

400

600

800

1000

1200

1400

1600

3010´]-2

[F-2 C

= 1e15, T = 20C, Perugia 2017FC2V,

Silvaco


=1e-5s, no avalanchetSynopsys, Perugia physics,

18


Tool Silvaco Synopsys +physics

Vdepl [V] ~240 ~160 ~400V



• useadvancedphysicsmodelsasusedbythePerugiagroup 10kHz

19


Tool Silvaco Synopsys +physics +default 𝛕

Vdepl [V] ~240 ~160 ~400V ~220

0 100 200 300 400 500 [V]bias V

0

200

400

600

800

1000

1200

1400

1600

3010´]-2

[F-2 C

= 1e15, T = 20C, Perugia 2017FC2V,

Silvaco



, no avalanchetSynopsys, Perugia physics, default



• useadvancedphysicsmodelsasusedbythePerugiagroup

• usethedefaultcarrierlifetimeagain10kHz

20



Vdepl [V] ~240 ~160 ~400V ~220

0 100 200 300 400 500 [V]bias V

0

200

400

600

800

1000

1200

1400

1600

3010´]-2

[F-2 C

= 1e15, T = 20C, Perugia 2017FC2V,

Silvaco




, avalanche ontSynopsys, Perugia physics, default




• usethedefaultcarrierlifetimeagain• addavalanche

10kHz

21



Vdepl [V] ~240 ~160 ~400V ~220




• usethedefaultcarrierlifetimeagain• addavalanche• comparetodatasimulatedbythePerugia

group

0 100 200 300 400 500 [V]bias V

0

200

400

600

800

1000

1200

1400

1600

3010´]-2

[F-2 C

= 1e15, T = 20C, Perugia 2017FC2V,

Silvaco




, avalanche ontSynopsys, Perugia physics, default

Synopsys, Perugia group data

Cfr.Bomben,28th RD50WS,Torino,June2016

10kHz


ComparisonofSimulators- PerugiaIrradiatedstructure– influenceoffrequencyonCV

0 100 200 300 400 500 [V]bias V

0

200

400

600

800

1000

1200

1400

1600

1800

3010´]-2

[F-2 C

, Perugia 20172/cmeq n1510´ = 1F = 0.45 kHz, t = -10 C, nC2V,

= 10 kHz - Synopsysn = 10 kHz - Silvacon = 0.45 kHz - Synopsysn = 0.45 kHz - Silvacon

• compareC-2Vwiththedefault10kHzand0.45kHzat-10oCforbothsimulators

• sametrendofhigherdepletionvoltageforhigherfrequency

• smallerinfluenceonSilvaco simulation• overallsmallinfluenceonly


ComparisonofSimulators– DelhiIrradiatedstructure– influenceoffrequencyonCV

0 500 1000 1500 2000 2500 3000 [V]bias V

0

200

400

600

800

1000

1200

1400

1600

1800

3010´]-2

[F-2 C

, New Delhi2/cmeq n1510´ = 1F = 0.45 kHz, t = -10 C, nC2V,

= 10 kHz - Synopsysn = 10 kHz - Silvacon = 0.45 kHz - Synopsysn = 0.45 kHz - Silvacon

• compareC-2Vwiththedefault10kHzand0.45kHzat-10oCforbothsimulators

• sametrendofhigherdepletionvoltageforlowerfrequency(oppositeofPerugia)

• smallerinfluenceonSilvaco simulation• hugeinfluencebyfrequency


ComparisonofSimulators- PerugiaIrradiatedstructure– IVcurves

• compareIVcurvesfrombothsimulatorsatdifferenttemperatures• smalldifferencebetweenthetwo• currentlowerinSynopsys• constantratio– differencecouldbedue

totemperaturescaling

Evaluationofthecurrentrelateddamagerateαat20C(norescalefortemperatureneeded)gives:

Tool Silvaco Synopsys

α[10-17 A/cm] 4.2±0.1 3.5±0.10 200 400 600 800 1000

[V]bias V

13-10

12-10

11-10

10-10

9-10

[A]

leak

I

, Synopsys vs Silvaco, Perugia 20172/cmeq = 1e15 nFIV,



ComparisonofSimulators- PerugiaIrradiatedstructure– chargecollectionefficiency

• comparechargecollectionefficiencyforPerugiamodelat-20oCand20oC

• normalised tocollectedchargeat200V-500V,beforeirradiation

• exactsamerisingedge• sametemperaturedependence• plateauefficiencydifferentby~5%

100 200 300 400 500 600 700 800 900 1000 [V]bias V

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

CC

E [%

]

, Synopsys vs. Silvaco, Perugia 20172/cmeq = 1e15 nFCCE,

Silvaco - T = 20 CSynopsys - T = 20 CSilvaco - T = -20 CSynopsys - T = -20 C


ComparisonofSimulators- DelhiIrradiatedstructure– chargecollectionefficiency

100 200 300 400 500 600 700 800 900 1000 [V]bias V

0

0.1

0.2

0.3

0.4

0.5

0.6

CC

E [%

]

, Synopsys vs. Silvaco, New Delhi2/cmeq = 1e15 nFCCE,

Silvaco - T = 20 CSynopsys - T = 20 CSilvaco - T = -20 CSynopsys - T = -20 C

• comparechargecollectionefficiencyforNewDelhimodelat-20oCand20oC

• bothdonotreachaplateau• efficiencydifferentby~14%at1000V


Summary

1. ComparingNewDelhiandPerugia2017radiationdamagemodels• depletionvoltagemuchhigherandmuchlargertemperaturedependenceusingNewDelhimodel• highercurrentsandnosaturationofcurrentupto1500Vgiventhehighdepletionvoltage• CCEis~80%forPerugiaand~50%forNewDelhi@1000Vand1x15neq/cm2

2. ComparingSynopsysandSilvaco TCADtools• CVagreesdowntothe%levelbeforeirradiation,afterirradiationsmalldifferenceswithPerugiamodel• IVdifferentbeforeirradiationduetodifferentτ value,afterirradiationclosetogether,compatiblewith2016data• CCEingoodagreementintherisingedge,plateauslightlydifferent,differenceis5%-14%

3. Outlook:• projecthasjuststarted,morecooperationplanned

• DEFPIXELSproject,EmbassyofFranceinGermanyandDAADProcope grantcall• comparethephysicsmodelsinmoredetailbetweenthetwosimulators• morecomplexstructurestospothigherorderdifferences• compareavalanchemodels

Thankyouforyourattention!

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